Saint Mary’s County (often abbreviated as St. Mary’s County), established in 1637, is a county located in the U.S. state of Maryland. As of the 2010 census, the population was 105,151. Its county seat is Leonardtown. The name is in honor of The Blessed Virgin Mary, the mother of Jesus as told in the Bible.
According to the U.S. Census Bureau, the county has a total area of 764 square miles (1,980 km), of which 357 square miles (920 km) is land and 407 square miles (1,050 km) (%) is water. It is the second-largest county in Maryland by total area.
Located on the St. Mary’s Peninsula, St. Mary’s County is largely bordered by water: the Patuxent River (northeast), the Chesapeake Bay (east), the Potomac River (southwest), and the Wicomico River (west). Its coastline has many coves, tidal creeks, bays, and inlets. Many coastal areas are made up of mixed clay-and-sand cliffs and bluffs, which protect many parts of the county from storm surges, however, there are low-lying coastal areas with coarse sand or gravel beaches or tidal marshlands, as well.
The interior of much of the county is hilly to varying degrees, with forests and agricultural fields. There also are coastal plain areas, much of which are under agriculture or under new development. Residential development has been increasing steadily for decades.
The county’s very extensive waters are mostly brackish, ranging from significant degrees of saltwater in tidal areas that are on or near the Chesapeake Bay, to a greater predominance of freshwater and lower-salt-concentrations in its interior tidal waterways and also further up its bordering rivers.
As of 2010, there were 105,000 people in St. Mary’s County, up from 84,000 in the year 2000. families residing in the county. The population density was 238 people per square mile (92/km²). There were 34,081 housing units at an average density of 36 persons/km² (94 persons/sq mi). The racial makeup of the county was 81.57% White, 13.92% African American, 0.34% Native American, 1.80% Asian, 0.07% Pacific Islander, 0.61% from other races, and 1.68% from two or more races. Hispanic or Latino of any race were 2.00% of the population. 14.8% were of American, 13.9% German, 13.3% English and 12.1% Irish ancestry.
There were 30,642 households out of which 25.90% had children under the age of 18 living with them, 46.10% were married couples living together, 15.10% have a woman whose husband does not live with her, and 34.90% were non-families. 29.40% of all households were made up of individuals and 12.90% had someone living alone who was 65 years of age or older. The average household size was 2.72 and the average family size was 3.14.
In the county, the population was spread out with 27.90% under the age of 18, 15.70% from 18 to 24, 29.50% from 25 to 44, 22.20% from 45 to 64, and 9.10% who were 65 years of age or older. The median age was 34 years. For every 100 females there were 101.80 males. For every 100 females age 18 and over, there were 119.10 males.
The median income for a household in the county was $54,706, and the median income for a family was $61,397. Males had a median income of $27,496 versus $23,035 for females. The per capita income for the county was $22,662. 7.20% of the population and 5.20% of families were below the poverty line. Out of the total people living in poverty, 28.40% are under the age of 18 and 19.10% are 65 or older.
As of the 2010 United States Census, there were 105,151 people, 37,604 households, and 27,084 families residing in the county. The population density was 294.4 inhabitants per square mile (113.7/km). There were 41,282 housing units at an average density of 115.6 per square mile (44.6/km). The racial makeup of the county was 78.6% white, 14.3% black or African American, 2.5% Asian, 0.4% American Indian, 0.1% Pacific islander, 1.0% from other races, and 3.2% from two or more races. Those of Hispanic or Latino origin made up 3.8% of the population. In terms of ancestry, 17.4% were Irish, 17.3% were German, 16.0% were English, 8.8% were American, and 5.2% were Italian.
Of the 37,604 households, 38.5% had children under the age of 18 living with them, 55.5% were married couples living together, 11.7% had a female householder with no husband present, 28.0% were non-families, and 21.8% of all households were made up of individuals. The average household size was 2.72 and the average family size was 3.18. The median age was 36.0 years.
The median income for a household in the county was $80,053 and the median income for a family was $89,385. Males had a median income of $61,971 versus $46,487 for females. The per capita income for the county was $34,000. About 4.7% of families and 7.1% of the population were below the poverty line, including 9.1% of those under age 18 and 7.3% of those age 65 or over.
St. Mary’s County is home to an Amish community in the Mechanicsville area in the northern part of the county that consists of eight church districts and about 1,000 people. The Amish first came to the area in 1940 after some members left the Amish community in Lancaster County, Pennsylvania over a conflict with schooling. The Amish in St. Mary’s County maintain dairy and produce farms along with small Amish businesses. There is also an Old Order Mennonite community in the county that stretches as far south as Loveville. In recent years, increasing development has threatened the Amish community.